Australia have not been the greatest of their forms in the recent past. After a 1-2 drubbing in the four-match Test series against India, they were knocked of the Champions Trophy in the group stage.

"(Smith) has got his biggest challenge coming up," Ponting was quoted as saying by cricket.com.au.

"An Ashes series as an Australian or England captain is the biggest thing that you play for and the biggest thing of your captaincy life," he added.

Ponting, who led Australia to 48 Tests wins - the most by any Australian, further proclaimed that Smith's career as captain will be judged on winning the Ashes.

"Fortunately or unfortunately, it's those series that you are remembered for as a leader and as a player as well," he asserted.

The 28-year-old has polished off 2,711 runs at an average of 73.27 with 12 centuries. However, his leadership turned a corner after the humiliation in Hobart last summer when South Africa defeated Australia to secure the Test and wrap up the series with a match to spare.

In 24 Tests as skipper, Smith has 12 wins, seven loss and five draws to his name. And Ponting seems impressed with his captaincy so far and concedes that Smith has done a terrific job while leading the team.